[Federal Register Volume 64, Number 208 (Thursday, October 28, 1999)]
[Notices]
[Pages 58106-58107]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-28228]


=======================================================================
-----------------------------------------------------------------------

NUCLEAR REGULATORY COMMISSION

[Docket No. 50-423]


Northeast Nuclear Energy Company, et al.; Millstone Nuclear Power 
Station, Unit No. 3, Environmental Assessment and Finding of No 
Significant Impact

    The U.S. Nuclear Regulatory Commission (the Commission) is 
considering issuance of an amendment to Facility Operating License No. 
NPF-49, issued to Northeast Nuclear Energy Company (NNECO or the 
licensee), for operation of the Millstone Nuclear Power Station, Unit 
No. 3 (MP3), located in New London County, Connecticut.

Environmental Assessment

Identification of the Proposed Action

    The proposed action would revise the analysis for the design basis 
loss-of-coolant accident (LOCA) to include the dose contribution from a 
previously unevaluated radioactivity release pathway to the 
environment. The licensee identified a potential pathway for post 
accident back-leakage of highly radioactive containment sump water from 
the Recirculation Spray System (RSS) to the Refueling Water Storage 
Tank (RWST). Since the RWST is

[[Page 58107]]

vented to the atmosphere, this pathway could contribute to an 
inadvertent release of radioactivity not previously accounted for in 
offsite dose calculations. Previously, the licensee had assumed no 
radiological consequences due to back-leakage. This revision adds the 
dose from RWST back-leakage to the LOCA analysis, as documented in the 
Final Safety Analysis Report (FSAR).
    The proposed action is in accordance with the licensee's 
application for amendment dated May 7, 1998, as supplemented by letter 
dated January 22, 1999.

The Need for the Proposed Action

    Pursuant to 10 CFR 50.59 licensees are required to obtain prior NRC 
approval of changes to the facility that involve an unreviewed safety 
question. The licensee determined that the back-leakage from RSS to the 
RWST involves an unreviewed safety question. Therefore, the licensee 
was required to obtain prior NRC approval for changes to the LOCA 
analysis and the FSAR to incorporate the dose consequences of the 
potential for back-leakage from the RSS to the RWST that had not been 
previously accounted for in offsite dose calculations.

Environmental Impacts of the Proposed Action

    The NRC has completed its evaluation of the proposed action and 
concluded that the contribution to the LOCA dose to the thyroid (most 
limiting organ) from the RWST back-leakage as calculated by the 
licensee is small (2.1 rem at the Low Population Zone (LPZ) and 0.9 rem 
at the Control Room). When added to the licensee's previously 
calculated doses, the affected LOCA doses to the thyroid are 11 rem at 
the LPZ and 12 rem at the Control Room. The increase are small when 
compared to, and these results continue to meet the acceptance criteria 
in, 10 CFR Part 100 for the offsite dose consequences and in 10 CFR 
Part 50, Appendix A, General Design Criterion (GDC) 19 for the control 
room. All other offsite and control room doses were unchanged. On this 
basis the staff determined there is no significant radiological 
environmental impact.
    The proposed action will not increase the probability or 
consequences of accidents, no changes are being made in the types of 
any effluents that may be released off site, and there is no 
significant increase in occupational or public radiation exposure. 
Therefore, there are no significant radiological environmental impacts 
associated with the proposed action.
    With regard to potential non-radiological impacts, the proposed 
action does not involve any historic sites. It does not affect non-
radiological plant effluents and has no other environmental impact. 
Therefore, there are no significant non-radiological environmental 
impacts associated with the proposed action.
    Accordingly, the NRC concludes that there are no significant 
environmental impacts associated with the proposed action.

Alternatives to the Proposed Action

    As an alternative to the proposed action the staff considered 
requiring the licensee to maintain zero back-leakage from the RSS to 
the RWST. Since this is the original analysis condition, this 
alternative is the same as the staff denying the proposed action (i.e., 
the ``no-action'' alternative). Zero back-leakage cannot be ensured for 
the valves between the RSS and the RWST; therefore, this alternative is 
impractical. Denial of the proposed action would result in no change in 
current environmental impacts. The environmental impacts of the 
proposed action and the alternative action are similar.

Alternative Use of Resources

    This action does not involve the use of any resources not 
previously considered in the ``Final Environmental Statement Related to 
the Operation of Millstone Nuclear Power Station, Unit No. 3,'' dated 
December 1984 (NUREG-1064).

Agencies and Persons Consulted

    In accordance with its stated policy, on September 23, 1999, the 
staff consulted with the Connecticut State official, Mr. Fred 
Scheuritzel of the Department of Environmental Protection, regarding 
the environmental impact of the proposed action. The State official had 
no comments.

Finding of No Significant Impact

    On the basis of the environmental assessment, the NRC concludes 
that the proposed action will not have a significant effect on the 
quality of the human environment. Accordingly, the NRC has determined 
not to prepare an environmental impact statement for the proposed 
action.
    For further details with respect to the proposed action, see the 
licensee's letter dated May 7, 1998, as supplemented by letter dated 
January 22, 1999, which are available for public inspection at the 
Commission's Public Document Room, The Gelman Building, 2120 L Street, 
NW., Washington, DC, and at the local public document rooms located at 
the Learning Resources Center, Three Rivers Community-Technical 
College, 574 New London Turnpike, Norwich, Connecticut, and the 
Waterford Library, 49 Rope Ferry Road, Waterford, Connecticut.

    Dated at Rockville, Maryland, this 22nd day of October 1999.

    For the Nuclear Regulatory Commission.
John A. Nakoski, Sr.,
Project Manager, Section 2, Project Directorate I, Division of 
Licensing Project Management, Office of Nuclear Reactor Regulation.
[FR Doc. 99-28228 Filed 10-27-99; 8:45 am]
BILLING CODE 7590-01-P